<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>css三角制作</title>
    <style>
        .box1{
            width: 0;
            height: 0;
            /* border: 10px solid rebeccapurple; */
            border-top: 10px solid pink;
            border-right: 10px solid red;
            border-bottom: 10px solid blue;
            border-left: 10px solid green;
        }
        .box2{
            width: 0;
            height: 0;
            border: 50px solid transparent;
            border-top-color: pink;
            margin: 100px auto;
        }
        .box3{
            width: 0;
            height: 0;
            border: 50px solid transparent;
            border-left-color: rebeccapurple;
            margin: 100px auto;
        }
    </style>
</head>
<body>
    <div class="box1"></div>
    <div class="box2"></div>
    <div class="box3"></div>
</body>
</html>